I do not like to retype fish every time I start terminal. I want fish on by default. How can I set fish shell as my default shell on a Mac?
From Terminal:
Add Fish to /etc/shells, which will require an administrative password:
sudo echo /usr/local/bin/fish >> /etc/shells
Make Fish your default shell with chsh:
chsh -s /usr/local/bin/fish
From System Preferences:
User and Groups → ctrl-click on Current User → Advanced Options...
Change Login shell to /usr/local/bin/fish

Press OK, log out and in again